1. Field of the Invention
This invention relates to freezer systems for the storage of frozen foods, and more particularly to a system for defrosting the evaporator in such freezer systems.
2. Description of the Related Art
During normal freezer system operation, hot gas refrigerant from a compressor is fed to a condenser which condenses the refrigerant into a liquid. The liquid refrigerant is fed to an evaporator where it expands to cool the evaporator and thus an adjacent freezer cabinet for the storage of frozen foods. Ice builds up on the outside of the evaporator, especially during high humidity periods. The ice is removed by defrosting the evaporator.
One method for defrosting the evaporator of a freezer system is to feed hot gas refrigerant from the compressor to the inside of the evaporator to melt the moisture which freezes on the outside of the evaporator during normal freezer operation. During both normal and defrost freezer operation, the hot gas from the compressor first passes through a water evaporating plate and coil assembly located over the compressor to heat the plate surface and evaporate the moisture drained from the outside of the evaporator during the defrost cycle. Such a system is shown in Modern Refrigeration and Air Conditioning, published by The Goodheart-Willcox Company, Inc., South Holland, Ill., 1979, pages 313-316. Another method for defrosting the evaporator is electrically-heated elements mounted adjacent the evaporator.
A need developed, however, for a more efficient defrosting system, especially for undercounter freezer systems for restaurants.